Research into gestures represents a multifaceted field comprising a wide range of disciplines and research topics, varying methods and approaches, and even different species such as humans, apes and monkeys. The aim of this volume (originally published as a Special Issue of <a href="/catalog/gest.5.1-2"><i>Gesture</i> 5:1/2 (2005)</a>) is to bring together the research in gestural communication in both nonhuman and human primates and to explore the potential of a comparative approach and its contribution to the question of an evolutionary scenario in which gestures play a significant role. The topics covered include the spontaneous natural gesture use in social groups of apes and monkeys, but also during interactions with humans, gestures of preverbal children and their interaction with language, speech-accompanying gestures in humans as well as the use of sign-language in human and nonhuman great apes. It addresses researchers with a background in Psychology, Primatology, Linguistics, and Anthropology, but it might also function as an introduction and a documentation state of the art for a wider less specialised audience which is fascinated by the role gestures might have played in the evolution of human language.